الفهرس 
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Abstract
Review of Literature .Rift valley fever (RVF) is an arthropod-born viral disease characterized by high mortality rate among lambs and calves and abortion of pregnant ewes and cows that was diagnosed widely in many sub-Saharan African countries and in Middle East in Egypt, Saudi-Arabia and Yemen. The disease is caused by RVF virus that belonged to genus Phlebovirus in the family Bunyaviridae.
In Egypt, control of RVF is being done using inactivated tissue culture adapted virus vaccine adjuvanted on aluminum hydroxide gel. A trial to develop an inactivated RVF vaccine using the widely used and low cost paraffin oil adjuvant and surfactant blends Arlacel A and Tween 80 in the formula of water in oil in water emulsions (W/O/W) that may produce an earlier and long term immune response.
Quality evaluation proved that both the prepared inactivated RVF paraffin oil adjuvanted vaccine and the locally prepared inactivated RVF vaccine adjuvanted with aluminum hydroxide gel were sterile, safe for mice and sheep and their potency in mice were 0.0002 ED50/ml and 0.0013 ED50/ml, respectively.
Groups of sheep were used for evaluation of the vaccine as follow:
Group (1): includes six animals, each inoculated with the prepared inactivated paraffin oil adjuvanted RVF vaccine.
Group (2): includes six animals, each inoculated with the local inactivated alum hydroxide gel adjuvanted RVF vaccine.
Group (3): includes two animals were kept as non-vaccinated control.Review of Literature
Group (4): includes three animals were pregnant at about two months of gestation, each were inoculated with the prepared inactivated paraffin oil adjuvanted RVF vaccine, left until they delivered and sera from their offspring lambs were used to estimate maternal immunity against RVF virus.
Vaccinated sheep were inoculated with both types of vaccine at a dose of 1ml by subcutaneous route that did not show any post-vaccination clinical signs or elevation in temperature.
Evaluation of humeral immune response in sheep till 12 months showed that:
1- Mean neutralizing index (NI) in sera studied by SNT started to rise from 1st week post vaccination (p.v.) and increased to the protective level at 2nd week p.v. for both vaccines, but mean NI reached the beak at 3d and 2nd month p.v. and extended at the protective level to 9th month and 7th month p.v. for the prepared inactivated paraffin oil adjuvanted RVF vaccine and the local inactivated aluminum hydroxide gel adjuvanted RVF vaccine, respectively.
2- Positive values in sera examined by ELISA appeared at 2nd week p.v. for both types of vaccines, then reached the beak level at 2nd week and 3rd week p.v. and extended at the positive level to 9th month and 9th month p.v. for the prepared inactivated paraffin oil adjuvanted RVF vaccine and the local inactivated aluminum hydroxide gel adjuvanted RVF vaccine, respectively. The result of ELISA was correlated with that obtained by SNT.
3- NI in sera from in three lambs borne from ewes vaccinated with inactivated paraffin oil adjuvanted RVF vaccine (without abortion) was at the protective level for 3 months of age and this result was confirmed and agreed with that obtained by ELISA.
Review of Literature
All the previous results gave the priority to the prepared inactivated paraffin oil adjuvanted RVF vaccine over the local inactivated aluminum hydroxide gel adjuvanted RVF vaccine. The newly prepared paraffin oil adjuvanted vaccine of RVF induced immunological enhancement without toxicity and give higher titer of antibody that remained for a much longer period extended for 9 months.